P Maiorano & S. Monechi: New Mi ocene species of Sphenolithus... , p. 103-107.
I

Journal of Nannoplankton Research, 19, 2, 1997.

NEW EARLY MIOCENE SPECIES OF SPHENOLITHUS
DEFLANDRE, 1952 FROM THE NORTH ATLANTIC OCEAN
Patrizia Nfaioran o, Dipartimento di Geologia e Geofisica, Via E. Orabona 4, 70125 Bari, Italy &Simonetta Jv!onechi, Dipartimento di Scienze del/a Terra, Via La Pira 4, 50121 Firenze, Italy

phic range (Figure 1).

Introduction

Sphenoliths are key biostratigraphic markers in the Early
Miocene (Rio et al. , 1990; Fomaciari et al. , 1990; Fornaciari& Rio, 1996; de Kaenel & Villa, 1996). We describe herein
two new species, Sphenolithus procerus and Sphenolithus
tintinnabulum from the Early Miocene secliments of DSDP
Leg 82, Site 563 (Bougault et al., 1985), located in the North
Atlantic Ocean on the west flank of the mid-Atlantic Ridge.
In the studied cores, the major lithologies areforaminifer-nannofossil ooze and chalk. Preservation ofcoccoliths is moderate and the assemblages are reasonably diverse. The new taxa were found within cores 15 to
13 in the CN1c and CN2 ZonesofOkada & Bukry (1980),equivalent to Zones NN2 and NN3 of Martini (1971). Detailed quantitative biostratigraphic results of the total assemblage at Site 563 will appear elsewhere (Maiorano &Monechi, in prep.).
In this note, the morphological features of S.
multispinatus sp. nov. (= S. multispinatus Fornaciari etal. , 1990, nomen nudum), S. cometa de Kaenel & Villa,
1996 and S. disbelemnos Fornaciari & ·Rio, 1996 havealso been described, because of their importance in theevolution of sphenoliths during the Early Miocene. In
particular, the taxonomic features ofS. multispinatus havebeen defined. This species has been differentiated from S
cometa based on its different morphology and stratigra-~<X:~·- . . . . ,.s ~t:!O\"'::E.._,

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NN1S. disbelemnos , S. p rocerus, S. cometa, S.
tintinnabulum and S. multisp inatus have also been re-cognised in the equatorial Indian Ocean ODP Site 758,
where their strati graphic distributions appeared comparable with those observed at Site 563 (Maiorano, 1996).
The sphenoliths described herein can be easily differentiated with the light microscope, alt110ugh they appear to be related by a common feature: they all have theapical spine formed by multiple elements rather than a single unit; however the orientation andextent of the apical•elements, as well as the morphology of the proximal shieldand its size in relation to the apical spine, are diagnostic
for the identification of the species. At present, there is noclear evidence of intergradational morphotypes among thedescribed sphenoliths and no phylogenetic relationships
have been inferred here.
Family SPHENOUTHACEAE Deflandre, 1952
Genus Sphenolithus Deflandre in Grasse, 1952

Sphenolithus procerus sp. nov.
Plate 1, Figures 1-3
Diagnosis: A species of Sphenolithus with a short proxi-mal shield and an extended apical spine composed ofelements parallel to the long axis of the sphenolith.
Description: In cross-polarised light (XPL), in the0°pOsition, the apical spine is divided in two by a medianextinction band. At the base oft he apical spine, a cycle ofvery short lateral elements can be recognised. At 45° tothe polarisation direction, the apical spine shows a threepart arrangement similar to S. dissimilis Bukry & Percival,
1971 and loses the extinction band.
Differentiation: S. procerus differs from S. dissimi/is byhaving a more-developed apical spine instead of anequivalent height between proximal shield and apicalspine, and from S. multispinatus by having less divergent
elements of the apical spine. It is differentiated from S.
cometa by its shorter proximal shield and thinner apical•spme.
Size: About 4-6Jlm long~ the proximal shield is about half
the height of the apical spine.
Derivation of name: From Latin procerus, slender.
Occun:ence: S. procen1s has a restricted range within theEarly Miocene Zone NN2 of Martini (1971) and Zone
CNlc ofOkada & Bukry (1980); the first specimens are
documented above the first occurrences (FOs) of S.
disbelemnos and of S. come/a. It ranges up to the upper
part of Zone NN2, above the last occurrence (LO) of S.
corneta.

Figure 1: Stratigraphic distribution of selected sphenoliths at DSDP Site563. Biozonal boundaries are traced according to Maiorano & Monechi(in prep.).

Holotype: Plate 1, Figure 3, DSDP Site 563, 14-6-120cm.
Type locality: DSDP Site 563, North Atlantic Ocean.
Range: Early Miocene, Zone NN2.

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Journal of Nannoplankton Research, 19, 2, 1997.

P Maiorano & S. Monechi: New Miocene species of Sphenolithus... , p. 103-1 c-Sphenolithus tintinnahulum SJ). nov.
Plate 1, Figures 4-6
Diagnosis: A species with a distinctive triangular outline

and a very short and multipartite apical spine.
Description : The proximal shield is both wider and higher
than the apical spine. When oriente<i at 45°tO the polarisation plane, a very short apical spine'is visible, sometimes
showing a three part arrangement. It shows intermed!atecharacteristics between S. disbelemnos and S. be/emnos;
the apical spine is similar to the former and the proximal
shield to the latter.
Differentiation : S. tintinnabulum differs from S.
disbe/emnos by its distinctive triangular outline and wider
proximal shield. It is differentiated from S. belemnos
Bramlette & Wilcoxon, 1967 by the multispinate structure and the length of the apical spine.
Size: About 2-4~ long.
Derivation of name: From Latin tintinnabulum , smallbell.
Occurrence: The species is recorded in the upper part ofZone CNl c and in the CN2 Zone. First occurrences of S.
tintinnabulum have been documented in the upper partof Zone NN2; the species partly eo-occurs with S. be/emnos
and highest occurrences are recorded slightly above theLO of S. belemnos.
Holotype: Plate 1, Figure4, DSDP Site 563 , 13-3-120cm.
Type locality: DSDP Site 563 , North Atlantic Ocean.
Range: Upper Zone NN2 and Zone NN3.
Sphenolithus multispinatus sp. nov.
Plate 1, Figures 14-16
Sphenolithus multispinatus Fornaciari et al., 1990, p.254, pl.3, figs
1-3 (nome n nudum).

Diagnosis: A species of Sphenolithus with a short, wide

proximal shield and a divergent apical spine.
Description: This sphenolith is characterised by a triangular proximal shield which is about half the height of
the apical spine. In XPL, in the ooposition, the apicalspine can be seen to be formed from multiple divergent
elements. In the 45° position., the multipartite apical spine
is birefringent. Lateral elements, perpendicular or obliqueto the median axis of the sphenolith, can be recognised.
Size: About 6-7Jlm long.
Differentiation : S. multispinatus differs from S. cometa
by having a distinCtive laterally-extended proximal shield
and a more-divergent apical spine.
Occurrence: The species is present in the Early Miocene
NN3-NN4 Zones; it first occurs just below the LO of S.
be/emnos and disappears slightly above the FO of S.
heteromorphus Deflandre, 1953.
Holotype: Plate 1, Figure 14, DSDP Site 563, 12CC-8cm.
Type locality: DSDP Site 563, North Atlantic Ocean.
Range: Upper Zone NN3 and lower Zone NN4.
Sphenolithus cometa de Kaenel & Villa, 1996
Plate 1, Figures 11-13
non Sphenolithus multispinatus Fornacia ri et al., 1990, p.254, pl.3,
fi gs 1-3.

Remarks: This species has a narrow proximal shield anda divergent apical spine which is higher t11an the proximal
shield. S cometa appears to have intermediate charac-teristics between S. disbe/emnos and S. multispinatus~ themorphology of the proximal shield is similar to ...
disbelenmos and t11e multipartite and extended apical spine
resembles tl1at ofS. multispinatus. According to de Kaenc ·& Villa (1996), S. multispinatus ofFornaciari et al. ( 19<)
may be synonymous with S. come la. However, we notedthat S. cometa, compared to S. multispinatus, has a narrower and higher proximal shield. Moreover, the two species have different stratigraphic ranges: S. cometa is recorded only within Zone·NN2 and last occurs before theFO of S. be/emnos.
Range: Early Miocene Zone NN2.
Sphenolithus dishelemnos Fornaciari & Rio, 1996
Plate 1, Figures 7-8
Sphenolithus dissimilis-Sphenolithus belemnos intergrade Rio t?lal.. 1990, pl.12, figs 2A-C.
Sphenolithus aubryae de Kaenel & Villa, 1996, p1.11 , fi gs 16-1'

Remarks: The recently described S. disbe/emnos is a dJs-

tinctive sphenolitl1 easily identified between crossed nicols
The diagnostic features of the species appear to be theorientation of the proximal elements, which are parallel tothe long axis of the sphenolith, and the very short andmultipartite apical spine, which is about half the height ofthe proximal shield. S. disbelemnos differs from S. belemno
by having a shorter and multipartite apical spine andparallel sides to the proximal shield. It differs from ~dissimi/is by having a narrower proximal shield and shorter
apical spine, and from the similar S. tintinnabulum by thewider proximal shield.
Range: At Site 563, S. disbelemnos first occurs in theuppermost NNI Zone and ranges up to the lower part ofNN3.
Acknowledgements

We wish to thank Dr. Jeremy Young for the critical revie"of the manuscript and his helpful suggestions, the ODPfor providing the deep-sea samples used in this study. OrB. Carrozzini for her assistance during SEM photographs.
and Dr. M. Marino for useful discussions and help. Special
thanks are given to Prof. N. Ciaranfi for encouraging Utis
research and supporting various phases of the work. Financial support was provided by the PhD Program of theUniversity ofBari and by M.U.R.S.T. 40%-60%, Prof. S
Monechi.
References
Bougault, H., Cande, S.C. & Scien tific Shipboard Party 1985
Site 563. IRDSDP, 82: 279-324.
Bramlette, M.N . & Wilcoxon, J.A. 1967. Middle Tertiary calcareous nann op lankton of the C ipero section, Trinidad.
W.I.. Tu lane Studies in Geology, 5: 93-131.
Bukry, D. & Percival, S.F. 1971. New Terti ary calcareous
nannofossils . Tulane Studies in Geology andPaleontology, 8: 123-146.
Fornaciari, E. , Raffi, I., Rio, D. , Villa , G. , Backman, J. &O lafsson, G. 1990. Quantitative d istributio n pattern of
Oligocene and Miocene calcareous nannofossils from western equatorial Indian Ocean. Proceedings of the ODP, SR
115: 237-254.
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P. Maiorano & S. Monechi: New Miocene species of Sphenolithus ..., p. 103-107.

Fornaciari , E. & Rio, D. 1996. Latest Oligocenc to early middle Miocene qu antit ati ve ca lcareous nannofossil
biostrati graphy in the Mediterranean region.
Al/icropaleontology, 42( 1): 1-36.
de Kaenel, E. & Villa, G. 1996. Oligocene-Miocene calcareousna nn ofossi l biostratigraphy and paleoecology from theIberia Abyssal Plain. Proceedings of the ODP. SR, 14 9 :79-145.
Maiorano, P. 1996. Biostratigrafia a nannofossili calcarei disuccessioni torbiditiche miocen iche nell ' Appenn ino
meridionale e di successioni pelagiche (DSDP e ODP)
mediterranee ed extra-mediterranee. PhD thesis, Universita
degli Studi di Bari: 177pp ..
Maiorano, P. & Monechi, S. In preparation. Quantitative cal-Journal of Nannoplankton Research, 19, 2, 1997.

ca reous nannofoss il biostratigraphy of Early-Middle
Miocene sedi ments from Leg 82 DSDP Site 563 •(North
Atlantic Ocean).
Martini, E. 1971. Standard Tertiary and Quaternary calcareousnannoplankton zonation. In : A. Farinacci (Ed.). Proceedlilgs ofthe Il Planktonic Con.forence, Roma, 1970, 0: 739-785.
Okada, H. & Bukry, D. 1980. Supplementary modification andintroduction of code numbers to the low-latitude coccolith
biostratigraphic zonation (Bukry, 1973 ; 1975). Marine
Al/icropaleontology, 5: 321-325.
Rio, D., Fornaciari, E. & Raffi, I. 1990. Late Oligocene through .
early Pleistocene calcareous nannofossils from westernequatorial Indian Ocean (Leg 115). Proceedings of theODP, SR. 115: 175-235 .

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I-"., :4P Maiorano & S. M.onfchr: New Miocene species of Sphenolithus ..., p. 103-107.

Journal of Nannoplankton Research, 19, 2, 1997.

PLATE 1
SEM (Scanning Electron Microscope). Scale bar · 1J.Un ·All light micrographs x3 125, except 9 and 10 which are x2500•Figs 1-3: Sphenolithusprocerus sp. nov.. DSDP Site 563, 14-6, 120crn. 1. XPL0°; 2. XPL45°. 3. Holotype SEM; Neg.
DGG95-14.
.

Figs 4-6: Sphenolithus tintinnabulum sp. nov.. DSDP Site 563, 13-3, 120crn. 4. Holotype SEM; Neg. DGG95-12.
•
5. XPL oo; 6. XPL 45°.
Figs 7-8: Sphenolithus disbelemnos Fornaciari & Rio. DSDP Site 563, 14-7, 35crn. 7. XPL oo; 8. XPL 45°.
Figs 9-10: Sphenolithus dissimilis Bukry & Percival. DSDP Site 563 , 16-4, 120crn. 9. XPL oo; 10. XPL 45°.
Figs 11-13: Sphenolithus cometa de Kaenel & Villa. DSDP Site 563 , 14-6, 120crn. 11. SEM. 12. XPL oo;
13. XPL 45°.
Figs 14-16: Sphenolithus multispinatus sp. nov.. DSDP Site 563 , 12CC, 8crn. 14. Holotype SEM; Neg. DGG94-12. 15.
XPL oo; 16. XPL 45° .

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Journal of Nannoplankton Research, 19, 2, 1997.

P Maiorano & S. Monechi: New Miocene species of Sphenolithus ... , p. I 03-107.

•PLATE 1.

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